1. Field of the Invention
The present invention relates in general to cutting tools used in metalworking operations. In particular, the invention relates to a cutting insert for a cutting tool, which has improved cutting properties. In one embodiment, the cutting insert also promotes chip control during the metalworking operation.
2. Description of the Related Art
A cutting tool used in a metalworking operation, such as a milling operation, typically includes a cutter body holding a plurality of cutting inserts. During the metalworking operation, the cutting inserts engage the workpiece to remove material therefrom. A cutting insert which requires a relatively large amount of force to remove material from the workpiece increases the power requirements of the cutting tool, and increases the wear of the cutting insert. Therefore, it would be desirable to provide a cutting insert that reduces the amount of force required to remove material from the workpiece.
U.S. Pat. No. 6,050,752 to DeRoche, issued Apr. 18, 2000, discloses a cutting insert in which the corner cutting edges are elevated relative to the side cutting edges. The corner cutting edges have the same height along their entire length. This design requires a relatively large amount of force to remove material from the workpiece.
To maximize efficiency and minimize the potential for damage caused by the material removed during the metalworking operation, cutting inserts are designed to remove this material and thereafter to reduce it into short segments known as chips. The design of cutting inserts to promote and control the formation of chips is referred to as chip control. There is a need for cutting inserts having improved chip control features.
U.S. Pat. No. 5,122,017 to Niebauer, issued Jun. 16, 1992, discloses a cutting insert having different geometries at different locations on the top surface. This design is intended to allow the cutting insert to have a desirable cutting surface in contact with the workpiece under differing parameters, not to improve chip control.
The invention relates a cutting insert for use in a cutting tool for a metalworking operation. The cutting insert comprises a polygonal body of hard wear resistant material. The body has a top surface and a bottom surface, and therebetween a peripheral wall including adjacent first and second wall portions. The intersection of the first wall portion and the top surface forms a first cutting edge, and the intersection of the second wall portion and the top surface forms a second cutting edge. The first cutting edge and the second cutting edge meet to form a high point which is adapted to engage a workpiece first during the metalworking operation.
In one embodiment of the invention, the cutting insert is indexable. The peripheral wall of the body includes side wall portions and corner wall portions. The intersections of the side wall portions and the top surface form side cutting edges, and the intersections of the corner wall portions and the top surface form corner cutting edges. The side cutting edges and the corner cutting edges meet to form high points. Each of the high points is adapted to engage a workpiece first during a metalworking operation.
The cutting insert of the invention reduces the amount of force required to remove material from the workpiece, thereby reducing the power requirements and associated cost of the metalworking operation. By reducing the cutting forces, wear and breakage of the cutting insert will be minimized and the life of the cutting insert will accordingly be improved.
In another embodiment of the invention, the top surface of the cutting insert has a topography that promotes chip control. The topography includes a plain adjacent to the cutting edges, and a plateau on the plain, which is, located inward from the cutting edges. The plateau is elevated relative to the plain and has a sloped side.